What would make radiator fan not to come on?
If your vehicle's radiator fan is not turning on, it could be due to a variety of reasons. The radiator fan plays a crucial role in keeping your engine cool, so it's important to identify and address the underlying issue. In this article, we'll explore the common causes for a non-functioning radiator fan and provide guidance on how to troubleshoot and resolve the problem.
Potential Causes for a Non-Working Radiator Fan
- Faulty Radiator Fan Relay or Fuse - The radiator fan is typically controlled by a relay or fuse, and if either of these components is malfunctioning, it can prevent the fan from turning on. Check the relay and fuse for any signs of damage or wear and replace them if necessary.
- Faulty Radiator Fan Motor - The radiator fan motor itself may be the culprit. Over time, the motor can wear out or become damaged, preventing it from turning on. You can test the motor by connecting it directly to the battery to see if it's functioning properly.
- Coolant Temperature Sensor Issue - The radiator fan is typically activated based on the coolant temperature. If the coolant temperature sensor is malfunctioning, it may not be triggering the fan to turn on when the engine reaches a certain temperature.
- Wiring or Electrical Connection Problems - Damaged or loose wiring, as well as poor electrical connections, can disrupt the flow of power to the radiator fan, causing it to not turn on.
- Thermostat Malfunction - A stuck or faulty thermostat can prevent the engine from reaching the temperature threshold required to activate the radiator fan.
By identifying the root cause of the issue, you can take the necessary steps to repair or replace the faulty component and restore the proper functioning of your radiator fan.
Troubleshooting Steps
- Check the Radiator Fan Relay and Fuse - Locate the relay and fuse responsible for the radiator fan and inspect them for any signs of damage or wear. Replace them if necessary.
- Test the Radiator Fan Motor - Disconnect the fan motor and connect it directly to the battery to see if it's functioning properly. If the motor doesn't turn on, it may need to be replaced.
- Inspect the Coolant Temperature Sensor - Use a multimeter to test the coolant temperature sensor and ensure it's providing the correct readings. Replace the sensor if it's malfunctioning.
- Examine the Wiring and Electrical Connections - Visually inspect the wiring harness and electrical connections leading to the radiator fan for any signs of damage or loose connections. Repair or replace any faulty components.
- Check the Thermostat - If the thermostat is stuck or not opening properly, it can prevent the engine from reaching the temperature required to activate the radiator fan. Replace the thermostat if necessary.
By following these troubleshooting steps, you can identify the root cause of the radiator fan issue and take the appropriate actions to restore its proper functioning. Remember to always consult your vehicle's service manual or a professional mechanic if you're unsure about any of the diagnostic or repair procedures.
Can a bad thermostat cause the radiator fan not to come on?
The thermostat acts as the control center for your HVAC system, including the fan. If the thermostat is faulty, it may not send the proper signals to the fan, preventing it from turning on or functioning at the desired speed.
Why is my radiator fan not kicking on?
Overheating can damage the radiator fan, wiring, or the fan motor. 2. Check the Coolant Level Low or no coolant can cause the fan to not turn on because some cars have a temperature sensor that only works when coolant is present.
Does a fuse control radiator fan?
Which fuse will rotate radiator fans in a car? On the inside of your fuse box (your car may have more than one) there should be a fuse location marked AUX FAN. This would be for electrical fans that cool the motor over a certain temperature.
Why is my radiator fan not turning on?
A faulty fan motor can result in the radiator fan not running when the AC is on (2). Fuse or relay issue: A blown fuse in the fan circuit or a faulty relay can disrupt the power supply to the radiator fan, causing it to fail to turn on. Checking the fan fuse and relay is an essential step in diagnosing the problem (2).
What tells the radiator fan to turn on?
The engine temperature should trigger the fan to turn on. It will also turn the fan off once the engine has cooled to under 200 degrees. You may have heard of a part called the radiator fan switch or temperature fan switch. This is linked to a thermostat and works much like your home's HVAC system.
How do I know if my radiator fan relay is bad?
If the cooling fan relay has failed, you may see warnings, such as the check engine light and the temperature warning light, pop up on the dash, but first, you may notice that the A/C stops cooling. More about that in the next paragraph. The check engine light illuminating may indicate a faulty cooling fan relay.
What controls a car radiator fan?
Mechanical (Belt-driven) Fans: These fans are connected directly to the engine and are driven by a belt. They spin at a speed proportional to the engine's RPM. Electric Fans: These fans are controlled by the ECM (Engine Control Module) based on the information from temperature sensors.
Can a bad temperature sensor cause a fan not working?
A signal from the coolant temperature sensor is what triggers the ECU to turn on the radiator fan, and if it's faulty, it can prevent the fan from working at all. Test the fan relay. Since the relay operates as a switch for the fan's power, a defective cooling fan relay won't energize the circuit.
How do I test if my radiator fan is working?
There are a few ways to test the radiator fan. You can connect the radiator fan to the car battery with jumper wires to see if the fan runs normally. You can connect a low impedance lamp in series with the motor, turn it through, and see if the lamp ever goes dark, which is the most sensible way.
How do I know if my radiator fan resistor is bad?
What common symptoms indicate you may need to replace the Cooling Fan Resistor?
- Cooling fan never stops running even with the ignition off.
- Cooling fan never kicks in and engine temperature increases abnormally.
